This invention relates to computers and computer terminals, and more particularly, to small, compact and light-weight terminal devices for computers and computer systems.
Flat display electroluminescent and plasma display devices are well-known and have long been incorporated into computer terminal devices, particularly for portable terminals and for portable computers. Such portable computers are sometimes called xe2x80x9csmartxe2x80x9d terminals or personal computers or work stations. While such flat screen devices substantially reduce the size of computer terminals, the standard keyboard, key pads, xe2x80x9cmice,xe2x80x9d and other input devices have required that even xe2x80x9cportablexe2x80x9d terminals be relatively bulky despite the thin screen display.
It is also well-known to provide a touch-sensitive display screen for computer terminals. By touching the screen at or near indicia displayed on the screen, the user can select actions or graphic display portions for further consideration or action. Thus, in response to a touch, a command can be selected from a menu for execution, a graphical element can be selected for enlargement, movement or replication, or a data file can be selected for processing. Such touch-responsive selections have the disadvantage, however, of being totally dependent on the specific application for which they were designed. General purpose input devices, such as typewriter-type keyboards, were therefore also necessary for generalized inputting.
In accordance with the illustrative embodiment of the present invention, a light, portable, compact computer terminal is provided by combining a flat screen display device with a touch-sensitive overlayer. All or a portion of the display surface is used to simulate a standard input device such as a standard xe2x80x9cq-u w-e-r-t-yxe2x80x9d typewriter keyboard or a touch-tone numerical telephone keypad. Simultaneously with the display of the simulated input device, the areas of the display corresponding to specific signals (alphanumerics, for example) are correlated with the generation of the corresponding signals, ASCII codes, for example.
It can be seen that a touch-sensitive screen in accordance with the present invention can serve all of the input and output needs of a computer terminal. A programmed microprocessor associated with the terminal can be used to provide the screen displays and generate the appropriate signals in response to touching the corresponding selected portions of the screen. Such a device can be considerably more compact than heretofore available computer terminals. True portability of a computer terminal in accordance with the present invention, particularly in a busy, and sometimes hostile, work environment, permits such a terminal to be used as an electronic clipboard, but with all of the processing power of a large computer.
In accordance with one feature of the present invention, the electronic clipboard terminal can be connected, by wires or by standard wireless technology, to minicomputers or large main frame computers to obtain the advantages of complex computing capability and access to large data bases.
In accordance with another feature of the present invention, the portable terminal can be used to simulate a standard keyboard, a standard telephone key pad, a standard numerical key pad, a stenographic machine, or any other standard finger-operated data input device. Moreover, the same screen which is used as a simulated input device can also be used as a standard output or display device, either at different times or at different locations (xe2x80x9cwindowsxe2x80x9d) on the display surface. Finally, such versatility is entirely under the control of software in a digital computer and hence can be called upon automatically in response to computer-derived signals. In this way, a standard simulated keyboard is displayed only at those times when alphabetic input is appropriate, a numerical key pad is displayed only when numeric input is appropriate, a telephone key pad is displayed only when a telephone number must be supplied, and so forth.